Bunnings

Concrete release agent is a substance used to keep concrete from sticking to forms and molds. It does this by coating them with a special type of oil or wax.

The material of the form affects how well a release agent performs. Wood forms generally require oils, such as straight refined, pale, paraffin-base mineral oil or oil emulsions. For steel forms, the release agent should contain a rust inhibitor and be water-free.

A release agent should permit easy stripping of the forms, preserve their use for long periods and prevent corrosion or staining of the concrete surface. It should also help produce a hard, nonpowdery concrete surface with a minimum number of defects.

Some concrete casters try different release concoctions, such as vegetable oil or petroleum jelly, but these materials can destroy the rubber mold over time and stain your concrete castings. To make a satisfactory substitution for a release agent, purchase two common oils and mix equal parts in a plastic container.

You should be able to use this concrete release agent in a variety of ways, including pouring concrete into the molds, using the molds to cast other items such as furniture or molding, and even to stamp concrete onto a concrete slab.